1) will try it
2) Oops, forgot to up this.
3) eaccelerator does what apc does, but has better mem usage and slightly better speeds from my personal experience.
4) new server is not actively being used at the moment, I will be running these after giving the server a few days of live traffic.

Formerly CyclingTribe

I remember doing a few other tweaks to my setup last year when optimising, so when I'm on the laptop next I'll try to add a few more bits. Might not be useful, but doesn't hurt to pass things on in case they are.